+++ /dev/null
----
-edit_link: ''
-title: WebSocket protocol x-afb-ws-json1
-origin_url: >-
- https://git.automotivelinux.org/src/app-framework-binder/plain/docs/protocol-x-afb-ws-json1.md?h=master
----
-
-<!-- WARNING: This file is generated by fetch_docs.js using /home/boron/Documents/AGL/docs-webtemplate/site/_data/tocs/apis_services/master/app-framework-binder-developer-guides-api-services-book.yml -->
-
-# The websocket protocol x-afb-ws-json1
-
-The WebSocket protocol *x-afb-ws-json1* is used to communicate between
-an application and a binder. It allows access to all registered apis
-of the binder.
-
-This protocol is inspired from the protocol **OCPP - SRPC** as described for
-example here:
-[OCPP transport specification - SRPC over WebSocket](http://www.gir.fr/ocppjs/ocpp_srpc_spec.shtml).
-
-The registration to the IANA is still to be done, see:
-[WebSocket Protocol Registries](https://www.iana.org/assignments/websocket/websocket.xml)
-
-This document gives a short description of the protocol *x-afb-ws-json1*.
-A more formal description has to be done.
-
-## Architecture
-
-The protocol is intended to be symmetric. It allows:
-
-- to CALL a remote procedure that returns a result
-- to push and receive EVENT
-
-## Messages
-
-Valid messages are made of *text* frames that are all valid JSON.
-
-Valid messages are:
-
-Calls:
-
-```txt
-[ 2, ID, PROCN, ARGS ]
-[ 2, ID, PROCN, ARGS, TOKEN ]
-```
-
-Replies (3: OK, 4: ERROR):
-
-```txt
-[ 3, ID, RESP ]
-[ 4, ID, RESP ]
-```
-
-Events:
-
-```txt
-[ 5, EVTN, OBJ ]
-```
-
-Where:
-
-| Field | Type | Description
-|-------|--------|------------------
-| ID | string | A string that identifies the call. A reply to that call use the ID of the CALL.
-| PROCN | string | The procedure name to call of the form "api/verb"
-| ARGS | any | Any argument to pass to the call (see afb_req_json that returns it)
-| RESP | any | The response to the call
-| TOKEN | string | The authorisation token
-| EVTN | string | Name of the event in the form "api/event"
-| OBJ | any | The companion object of the event
-
-Below, an example of exchange:
-
-```txt
-C->S: [2,"156","hello/ping",null]
-S->C: [3,"156",{"response":"Some String","jtype":"afb-reply","request":{"status":"success","info":"Ping Binder Daemon tag=pingSample count=1 query=\"null\"","uuid":"ec30120c-6997-4529-9d63-c0de0cce56c0"}}]
-```
-
-## History
-
-### 14 November 2019
-
-Removal of token returning. The replies
-
-```txt
-[ 3, ID, RESP, TOKEN ]
-[ 4, ID, RESP, TOKEN ]
-```
-
-are removed from the specification.
-
-## Future
-
-Here are the planned extensions:
-
-- add binary messages with cbor data
-- add calls with unstructured replies
-
-This could be implemented by extending the current protocol or by
-allowing the binder to accept either protocol including the new ones.
-
-## Javascript implementation
-
-The file **AFB.js** is a javascript implementation of the protocol.
-
-Here is that code:
-
-```javascript
-/*
- * Copyright (C) 2017-2019 "IoT.bzh"
- * Author: José Bollo <jose.bollo@iot.bzh>
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-AFB = function(base, initialtoken){
-
-if (typeof base != "object")
- base = { base: base, token: initialtoken };
-
-var initial = {
- base: base.base || "api",
- token: base.token || initialtoken || "HELLO",
- host: base.host || window.location.host,
- url: base.url || undefined
-};
-
-var urlws = initial.url || "ws://"+initial.host+"/"+initial.base;
-
-/*********************************************/
-/**** ****/
-/**** AFB_context ****/
-/**** ****/
-/*********************************************/
-var AFB_context;
-{
- var UUID = undefined;
- var TOKEN = initial.token;
-
- var context = function(token, uuid) {
- this.token = token;
- this.uuid = uuid;
- }
-
- context.prototype = {
- get token() {return TOKEN;},
- set token(tok) {if(tok) TOKEN=tok;},
- get uuid() {return UUID;},
- set uuid(id) {if(id) UUID=id;}
- };
-
- AFB_context = new context();
-}
-/*********************************************/
-/**** ****/
-/**** AFB_websocket ****/
-/**** ****/
-/*********************************************/
-var AFB_websocket;
-{
- var CALL = 2;
- var RETOK = 3;
- var RETERR = 4;
- var EVENT = 5;
-
- var PROTO1 = "x-afb-ws-json1";
-
- AFB_websocket = function(on_open, on_abort) {
- var u = urlws;
- if (AFB_context.token) {
- u = u + '?x-afb-token=' + AFB_context.token;
- if (AFB_context.uuid)
- u = u + '&x-afb-uuid=' + AFB_context.uuid;
- }
- this.ws = new WebSocket(u, [ PROTO1 ]);
- this.url = u;
- this.pendings = {};
- this.awaitens = {};
- this.counter = 0;
- this.ws.onopen = onopen.bind(this);
- this.ws.onerror = onerror.bind(this);
- this.ws.onclose = onclose.bind(this);
- this.ws.onmessage = onmessage.bind(this);
- this.onopen = on_open;
- this.onabort = on_abort;
- }
-
- function onerror(event) {
- var f = this.onabort;
- if (f) {
- delete this.onopen;
- delete this.onabort;
- f && f(this);
- }
- this.onerror && this.onerror(this);
- }
-
- function onopen(event) {
- var f = this.onopen;
- delete this.onopen;
- delete this.onabort;
- f && f(this);
- }
-
- function onclose(event) {
- for (var id in this.pendings) {
- try { this.pendings[id][1](); } catch (x) {/*TODO?*/}
- }
- this.pendings = {};
- this.onclose && this.onclose();
- }
-
- function fire(awaitens, name, data) {
- var a = awaitens[name];
- if (a)
- a.forEach(function(handler){handler(data);});
- var i = name.indexOf("/");
- if (i >= 0) {
- a = awaitens[name.substring(0,i)];
- if (a)
- a.forEach(function(handler){handler(data);});
- }
- a = awaitens["*"];
- if (a)
- a.forEach(function(handler){handler(data);});
- }
-
- function reply(pendings, id, ans, offset) {
- if (id in pendings) {
- var p = pendings[id];
- delete pendings[id];
- try { p[offset](ans); } catch (x) {/*TODO?*/}
- }
- }
-
- function onmessage(event) {
- var obj = JSON.parse(event.data);
- var code = obj[0];
- var id = obj[1];
- var ans = obj[2];
- AFB_context.token = obj[3];
- switch (code) {
- case RETOK:
- reply(this.pendings, id, ans, 0);
- break;
- case RETERR:
- reply(this.pendings, id, ans, 1);
- break;
- case EVENT:
- default:
- fire(this.awaitens, id, ans);
- break;
- }
- }
-
- function close() {
- this.ws.close();
- this.ws.onopen =
- this.ws.onerror =
- this.ws.onclose =
- this.ws.onmessage =
- this.onopen =
- this.onabort = function(){};
- }
-
- function call(method, request, callid) {
- return new Promise((function(resolve, reject){
- var id, arr;
- if (callid) {
- id = String(callid);
- if (id in this.pendings)
- throw new Error("pending callid("+id+") exists");
- } else {
- do {
- id = String(this.counter = 4095 & (this.counter + 1));
- } while (id in this.pendings);
- }
- this.pendings[id] = [ resolve, reject ];
- arr = [CALL, id, method, request ];
- if (AFB_context.token) arr.push(AFB_context.token);
- this.ws.send(JSON.stringify(arr));
- }).bind(this));
- }
-
- function onevent(name, handler) {
- var id = name;
- var list = this.awaitens[id] || (this.awaitens[id] = []);
- list.push(handler);
- }
-
- AFB_websocket.prototype = {
- close: close,
- call: call,
- onevent: onevent
- };
-}
-/*********************************************/
-/**** ****/
-/**** ****/
-/**** ****/
-/*********************************************/
-return {
- context: AFB_context,
- ws: AFB_websocket
-};
-};
-```
Code Review / AGL / documentation.git / blobdiff